The present invention generally relates to a copying apparatus and more particularly, to a variable magnification copying apparatus arranged to shift lens positions according to a set converted magnification, and to return the lens to an equal size magnification or life size position based on a result of comparison between the detected or inputted original document size and the previously stored original document size.
Recently, with the diversification in the functions of copying apparatuses, there have been commercialized many copying apparatuses having the magnification converting function capable of copying an original document of a predetermined size onto copy paper sheets on an enlarged or contracted scale. The copying apparatus of the above type is generally so arranged that the size of an original document to be copied is detected or inputted by a sensor provided at an original document platform or an input key disposed at an operating section, thereby to calculate the converted magnification by the above original document size and the set copy paper sheet size, or to input the converted magnification by "zoom" keys provided at the operating section, and thus, by shifting the lens to the position corresponding to the converted magnification set in the manner as described above, copying at the magnification converted as desired may be effected. Accordingly, when the copying at the converted magnification is completed, it becomes necessary to keep the lens returned at a position of an equal or life size magnification at 1:1 which is normally utilized most frequently for copying.
However, the prior art variable magnification copying apparatuses as referred to above have been provided with no functions to control the lens positions after completion of the copying operation. Therefore, there has been such a disadvantage that, for example, in the case where an original document of B5 size is first copied on an enlarged scale, onto a copy paper sheet of A4 size and thereafter, a next operator is to effect copying of another original document of A4 size at an equal size or life size magnification, if the previous operator did not return the lens to the position for the equal size magnification after completion of the copying at the converted magnification, and the present operator starts the copying operation without ensuring the converted magnification, copying at erroneous size takes place, thus resulting in prolongation of time required for the copying, with a consequent rise in the running cost of the copying apparatus, and a reduction of the operating efficiency.